New Mexico is neighboring and also generally a blue state for quite some time. It is similarly lopsided in terms of population concentration in the central city

New Mexico is neighboring and also generally a blue state for quite some time. It is similarly lopsided in terms of population concentration in the central city, but I think the phenomenon is older than this in both states. Colorado and New Mexico both have a history of leaning pretty libertarian in a classical sense which I think lead to a lot of the progressive policy you see today. It might be attributable to the fact that both are Rocky Mountain states that aren't all that easy to settle and so have a history of a fiercely independent population. In modern times that shifted towards a sort of cultural capital status that has attracted a lot of younger people. It is perhaps also a factor that both states are relatively multicultural compared to other US states in the region (this applies to AZ and TX as well to some extent, so clearly there are multiple things going on). A common go-to example of New Mexico's libertarian tradition was the legalization of same-sex marriage in this very Catholic state by a supreme court ruling, after some county clerks started issuing same-sex marriage licenses on their own initiative because they didn't think the law prohibited it. This kind of thing is sometimes viewed as apathy but is more charitably seen as part of a general attitude towards permissiveness.